Hydrogenation of organic compounds

ABSTRACT

NOVEL SULFIDED HYDROGENATION CATALYSTS ARE FORMED BY IMPREGNATING A SUITABLE SUPPORT MATERIAL WITH AN AQUEOUS SOLUTION OF A SALT OF A TRANSITION METAL; HEAT-TREATING THE IMPREGNATED SUPPORT AT A TEMPERATURE ABOVE 500* F. TO FORM CHEMICAL COMPLEXES ON THE SURFACE OF THE SUPPORT AND TO DRIVE OFF MOISTURE AND ABSORBED OXYGEN; CONTACTING THE SUPPORTED METAL COMPLEX WITH HYDROGEN SULFIDE; ACTIVATING THE SURFACE COMPLEX BY CONTACTING THE SUPPORTED METAL SULFIDE COMPLEX WITH A SOLUBLE ORGANOMETALLIC COMPOUND WHEREIN THE METAL CONSTITUENT IS SELECTED FROM GROUPS I, II AND III OF THE PERIODIC CHART OF THE ELEMENTS, AND THEREAFTER TREATING THE ACTIVATED SUPPORT MATERIAL IN THE PRESENCE OF A GASEOUS STREAM CONTAINING HYDROGEN AT A TEMPERATURE OF AT LEAST 300* F. TO FORM A HIGHLY STABLE HETEROGENEOUS SULFIDED CATALYSTS. THE NOVEL SUPPORTED CATALYSTS OF THE INSTANT INVENTION HAVE BEEN FOUND TO BE HIGHLY ACTIVE FOR THE HYDROGENATION OF ORGANIC FEEDSTOCKS CONTAINING SULFUR UNDER EXTREMELY MILD CONDITIONS.

United States Patent HYDROGENATION OF ORGANIC COMPOUNDS Joseph K.Mertzweiller and Horace M. Tenney, Baton Rouge, La., assignors to EssoResearch and Engineering Company No Drawing. Continuation-impart ofapplication Ser. No.

761,793, Sept. 23, 1968, which is a continuation-inpart of applicationsSer. No. 674,097, Oct. 10, 1967, and Ser. No. 761,792, Sept. 23, 1968.This application Jan. 7, 1970, Ser. No. 1,281

Int. Cl. C07c /02 US. Cl. 252-431 27 Claims ABSTRACT OF THE DISCLOSURENovel sulfided hydrogenation catalysts are formed by impregnating asuitable support material with an aqueous solution of a salt of atransition metal; heat-treating the impregnated support at a temperatureabove 500 F. to form chemical complexes on the surface of the supportand to drive off moisture and absorbed oxygen; contacting the supportedmetal complex with hydrogen sulfide; activating the surface complex bycontacting the supported metal sulfide complex with a solubleorganometallic compound wherein the metal constituent is selected fromGroups I, II and III of the Periodic Chart of the Elements, andthereafter treating the activated support material in the presence of agaseous stream containing hydrogen at a temperature of at least 300 F.to form a highly stable heterogeneous sulfided catalyst. The novelsupported catalysts of the instant invention have been found to behighly active for the hydrogenation of organic feedstocks containingsulfur under extremely mild conditions.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is acontinuation-in-part of US. Ser. No. 761,793 which application is acontinuation-in-part of Ser. No. 674,097, filed Oct. 10, 1967, nowabandoned and Ser. No. 761,792, both of which were filed Sept. 23, 1968and are now abandoned.

BACKGROUND OF THE INVENTION This invention relates to a new and usefulprocess for the preparation of high activity sulfided catalysts suitablefor reactions between hydrogen and hydrocarbons and particularly for thehydrogenation, or hydrogen addition, to organic compounds containingnitrile groups, carbonyl groups, aromatic, acetylenic or olefiniclinkages. It is also concerned with the novel catalysts so produced, aswell as the processes for using these catalysts.

More particularly, this invention relates to impregnating a suitablesupport, as hereinafter defined, with a transition metal, contacting thesupported metal complex with hydrogen sulfide and thereafter treatingthe supported sulfided catalyst with an organometallic compound undersuch conditions as to form a stable heterogeneous sulfided catalyst.Specifically, this invention relates to impregnating a suitable supportmaterial with a transition metal, contacting the supported metal comat atemperature of at least 500 F. to drive ofi moisture and absorbedoxygen; contacting the supported metal complex with hydrogen sulfide;activating the supported metal sulfide complex with an organometalliccompound and thereafter treating the activated species in the presenceof a gaseous stream containing hydrogen under critically definedconditions in order to form the highly active, stable hydrogenationcatalyst of the instant invention. This final step which comprisestreating the activated supported catalyst in the presence of hydrogenunder critically defined conditions is termed fixation and 3,677,969Patented July 18, 1972 DESCRIPTION OF THE PRIOR ART Various heavymetals, especially transition metals, have been previously described asuseful for conducting catalytic reactions. Hydrogenation catalysts haveincluded solid metals, slurries of metals, and metals dispersed onsupports. Solid metal catalyst had been prepared by contacting oxides ofthe desired metal with reducing gases, e.g., carbon'monoxide, orhydrogen, or both. Slurries suitable as catalyst have been prepared bycontacting anhydrous solutions of organometallic compounds of thedesired metal with organoaluminum compounds, these being broughttogether to form slurried catalysts. Metals have been provided onsupports by impregnation of support with anhydrous solutions of thesalts of the desired metal, this being found by reduction of the saltsto produce deposition of metallic metal.

In Canadian Pat. No. 697,780, which issued Nov. 10, 1964, methods aredescribed for improving the activity of cobalt and for convertingcertain inactive metals, i.e., manganese and molybdenum, into activehydrogenation catalysts. In typical reactions, slurried catalyticmixtures are produced by forming anhydrous solutions of soaps of thedesired metal, and the desired organometallic reducing agent, and thencontacting the two solutions together to form catalytic reactionmixtures. In accordance with one of the methods, a support isimpregnated by contact with anhydrous or nonaqueous solution of a soapof the desired metal, and with an organometallic reducing agent, such asorganoaluminum compound, to produce a loosely supported reaction productmixture of dispersed metals. In other techniques, supports areimpregnated with soaps of the desired metal, and the sup port thencontacted with a solution of the organometallic reducing agent toproduce supported catalytic mixtures.

While these catalysts are moderately active hydrogenation catalysts,there are nonetheless a number of disadvantages associated with theiruse. For one thing, the materials, in all the phases of their use arehighly pyrophoric and the slurries must be formed in an oxygenfreeatmosphere. Also, the catalytic materials formed are highly pyrophoric.Thus, the catalytic product of the reaction is an insoluble pyrophoricsolid which is highly reactive whether in slurry or supported form.Moreover, the material used in forming the catalysts are quiteexpensive, to say nothing of the cost involved, due to the extraprecautions which must be taken in handling the materials. Furthermore,the organic solvents which are used are highly flammable.

In US. Pat. 3,415,759 there is disclosed a method for preparing ahydrogenation catalyst by depositing cobalt carboxylate on adiatomaceous earth support and heating the supported cobalt carboxylateat a temperature between about and C. and thereafter reacting the thusheat-treated product with an aluminum alkyl. However, when temperaturesmaterially above about 160 C. are employed to dry the catalysts, thecatalyst becomes progressively deactivated, particularly insofar as thehydrogenation of high molecular weight compounds are concerned.

In our copending application Ser. No. 880,933, filed Nov. 28, 1969,which application is a continuation-inpart of US. application Ser. No.674,098, filed Oct. 10, 1967, now abandoned, new and improvedhydrogenation catalyst employable in heterogeneous liquid and gas phasereaction systems are described. When transition metal salts, i.e. saltsof Groups I-B, IV-B, V-B, VL-B and VII-B metals are deposited onsuitable supports, contacted with organoaluminum compounds and treatedin the presence of hydrogen at high temperatures, they become veryhighly active, and form catalysts which can' produce hydrogenation oforganic compounds even under very mild conditions of temperature andpressure. Unfortunately, these catalysts are very sensitive toimpurities, especially those usually found in refinery and chemicalprocess streams, particularly high sulfur content streams. Consequently,they tend to lose their activity.

In our copending application Ser. No. 1,282, filed I an. 7, 1970 whichapplication is a continuation-in-part of US. Ser. No. 674,097, filedOct. 10, 1967, now abandoned, improved heterogeneous catalysts havingreduced sensitivity to sulfur compounds and other poisons are described.These catalysts are formed by an additional activation stepviz.,hydrogen sulfide activation, of the catalysts described in applicationSer. No. 880,933, supra.

In the formation of the base catalyst, it was thus found that a highactivity hydrogenation catalyst could be formed by the steps generallycomprising: impregnating suitable support materials with salt solutionsof Group VIII metals; heat-treating the impregnated supports to formchemical complexes at the surface of the support and to drive off theliquid and adsorbed oxygen; activating and further modifying the surfacecomplex by contact of the impregnated supports with liquid solubleorganometallic compounds wherein a metal constituent is selected fromGroups I, II and III of the Periodic Chart of the Elements; and thencontacting the activated supported metal complex in the presence ofhydrogen at elevated temperatures. The high activity of the so activatedcatalyst is thus believed to result from a reduced complex containingaluminum, with either or both the Group VIII and the aluminum metalbonded to the support. An additional and final step of sulfiding theabove defined catalytic species, as described by application Ser. No.1,282 filed, Ian. 7, 1970 produced a catalyst of reduced sulfursensitivity. Such sulfur resistant species is believed to result fromthe formation of a few sulfurcontaining complex.

While this new sulfur resistant species of catalysts, supra, is farsuperior to the earlier nonsulfied varieties for use insulfur-containing feedstreams, it nonetheless leaves something to bedesired. Thus, in preparing the sulfur-resistant heterogeneous species,soluble complexes of the metal are also formed and lost. This representswaste and inefliciency, baed on total metal. In addition, it is foundthat the catalyst is less stable and activity declines more than desiredwhen hydrogenation reactions are conducted at elevated temperatures.

The present invention obviates the foregoing and other deficiencies andis based on the further discovery that a transition metal species can befirst sulfided and thence activated with an organoaluminum compound toprovide a more stable heterogeneous sulfided catalyst of even furtherenhanced hydrogenation activity, and even less sensitivity to sulfur andother poisons. Accordingly, the present catalysts can be used for thehydrogenation of organic compounds, including especially thosecontaining aromatic or olefinic linkages, even under very mildconditions of temperature and pressure, and in the pres ence of sulfur.It is thus an object to provide more stable, easy to handle catalystsfor use in a wide variety of processes, including selectivehydrogenation, hydrogenation, dehydrogenation, isomerization,hydrodesulfurization, hydrodenitrogenation, hydrocracking, reforming,aromatization, and hydrogen transfer. A further object is to provide aneflicient process for forming high activity catalysts, the processutilizing relatively cheap, readily available forms of metal saltsapplicable in aqueous media.

SUMMARY OF THE INVENTION It has now been discovered that novel sulfidedhydrogenation catalysts exhibiting unusually high activity and stabilitymay be prepared by impregnating a suitable support material, ashereinafter defined, with an aqueous solution of a salt of a transitionmetal or by precipitating or coprecipitating transition metal salts fromsuch solutions as gels; heat-treating the impregnated support at atemperature of at least about 500 F. to form chemical complexes on thesurface of the support and to drive off moisture and absorbed oxygen;contacting the supported metal complex with hydrogen sulfide; actviatingthe supported metal sulfide complex by contacting the impregnatedsupports with a soluble organometallic compound wherein the metalconstituent is selected from Groups I, II and III of the Periodic Chartof the Elements, and thereafter treating the activated sulfided supportmaterial in the presence of hydrogen at a temperature of at least 300 F.The present invention is based on the discovery that a highly tenaceouschemical bonding can be formed between the surface of certain types ofsupports and the transition metals and the metallic constituent of thesoluble organometallic compound when the metals are applied to thesupports under the sequence and critically defined conditions of theinstant invention. While suitable loadings are quite feasible,precipiration or coprecipitation of a transition metal salt with a gelprovides greater flexibility in metal content. Also, the gel, afterdehydration and thermal activation, activates readily and substantiallycompletely. Activity and selectivity are quite high as compared withimpregnation.

In the sequence of process steps, a supporting material having a surfacearea of at 'least 5 square meters per gram and containing at least 0.1millirnole of hydroxyl groups per gram of support is first impregnatedwith a watersoluble species of a transition metal, preferably a GroupI-B, IVB, V-B, VI-B, VII-B or Group VIII metal. Water has been foundparticularly suitable for the application of the Group IB, IVB, V-B,VI-B, VII-B or Group VIII metals to the support by contacting orimmersing the support in an aqueous solution of a salt of the desiredmetal. Suitablly, the support is impregnated with from about 0.1 toabout 20% metal, and preferably from about 2 to about 10% metal, basedon the total weight of the deposited metal and support.

The impregnated support is then preconditioned by heating theimpregnated support at a temperature of at least about 500 F. in orderto drive off moisture and absorbed oxygen from the catalyst surface.

Thereafter, the sulfiding step is conducted by contacting the supportedmetal complex with hydrogen sulfide in the vapor phase at temperaturesranging preferably at from about 400 F. to about 1000 F, and morepreferably from about 600 F. to about 800 F. At higher temperatures theactivity of the catalyst may be diminished. The sulfiding step iscarried out in a gaseous medium containing hydrogen sulfide, preferablyin quantities ranging from about 0.1 to about 20% concentration, andmore preferably in quantities ranging from about 1% to about 10%concentration. A typical sulfiding mixture is about 10% hydrogensulfide/% hydrogen. Higher concentrations of hydrogen sulfide are notgenerally desirable due to the practical necessity of removing the heatsof reactions.

Virtually any sulfur-containing compound, or even elemental sulfur, canbe used, e.g., in a hydrogen atmosphere, in forming the desired hydrogensulfide. Hydrogen sulfide can be formed in gases at higher temperatures,and thence the temperature of the gas reduced to effect the sulfidingstep.

After the catalyst has been sulfided at high temperatures, it isgenerally always observed that loosely held sulfide or sulfur compoundsare present. If the catalyst is stripped with hydrogen, nitrogen orinert gases at temperatures of 400-1000 F. after the fiow of hydrogensulfide is removed, the exit gas will continue to show the presence ofappreciable concentrations of hydrogen sulfide for a considerable periodof time. For the most effective practice of this invention, it isdesirable to remove as much of this loosely held sulfur as possible. Ifit is not removed, it will consume metal alkyl compound in thesubsequent activation step. The loosely held sulfur compounds areconveniently removed by stripping with hydrogen or other gases in theabsence of added sulfur at temperatures of 400-1000 F. for sufficienttime to get the residual hydrogen sulfide in the off-gas to sufficientlylow levels. At this point, the catalyst is properly sulfided and can berepresented by a composition M8,, in which M is the transition metal, Sis sulfur, and n is 0.5 to 3. In the Sulfided form the transition metalM will generally be at a lower valence state than the oxide form of M.

The preconditioned sulfided catalyst is then activated by contacting theimpregnated supports with a soluble organometalllic compound wherein themetallic constituout is selected from Groups I, II and III of thePeriodic Chart of the Elements and 'Wherein the metallic constituent hasan atomic number of from 3 to 50. Preferably, the organic constituent ofthe organometallic compound are alkyl groups, particularly linear alkylgroups having from 1 to about '12 carbon atoms. Only the organo metalliccompounds of Groups I, II and III which are soluble in hydrocarbon o-rsoluble in or complex with ethers are suitable for the method of thisinvention. These are the organometallic species which are characterizedby predominantly covalent bonding between the metal and the alkyl and/or hydride groups. The preferred metallic'cons'tituent of theorganometallic compound is aluminum.

Thereafter, the activated supported material is treated by heating theactivated supported material at a temperature of at least 300 F. in thepresence of a gaseous stream containing hydrogen. Preferably, theactivated supported material is treated in the presence of hydrogen at atemperature above 400 F., more preferably above 800 F. and still morepreferably at a temperature in the range of from about 800 to about 1200F. for a period of time in the range of from about 1 to about 100 hours.Surprisingly, it has been found that under these high severityconditions, i.e. treating the activated supported catalyst at atemperature above 800 and up to about 1200 F. in the presence ofhydrogen, the activity of these catalysts is not significantly decreasedand, in fact, generally increases as the treating severity is increased.

The sulfided, organoaluminurn activated catalyst is then ready for usein a suitable reaction system for producing hydrogenation (alsodehydrogenation) or other reactions. These catalysts, especially thoseformed by use of aqueous solutions of the salts of iron, cobalt andnickel, have proven themselves of exceptionally high activity. Olefinswhether singular or multiple linkage compounds, aliphatic or cyclic havebeen readily hydrogenated to paraffins, and aromatic compounds have beensaturated to produce the corresponding cycloalkanes. Acetylem'ccompounds, whether of singular or multiple linkage, or aliphatic orcyclic, can also be hydrogenated. This is generally so even Where thefeedstocks utilized in the reactions contained high concentrations ofsulfur. The activity of the catalysts was virtually unimpaired evenafter long periods of use. Further, catalysts formed with salts ofcobalt and iron in the initial step have proven highly satisfactorydespite the normally low activity attributed to cobalt and the evenlower activity attributed to iron for producing hydrogenation reactions.

There is some interference, however, by some types of sulfur compoundsand the normal high activity can be impeded very gradually. Thus,although these catalysts normally have good resistance to sulfur typesand concentrations normally present in petroleum stocks, there isevidence that certain sulfur compounds, e.g. mercaptans, tend to beadsorbed on the catalyst and may thereby cause some loss of activity.Even this effect, however, can be curtailed or eliminated by operatingthe catalysts at temperatures and pressures at which adsorption of thesulfur compounds is not favored. The conditions necessary to achievethis effect will vary with different feedstocks and different sulfurcompounds.

In addition, it is entirely feasible to regenerate these catalysts bystripping with hydrogen at eleveated temperatures, e.g. at temperaturesof from about 400 to about 1000 F. The catalysts are amenable tocomplete regeneration by (1) oxidizing with air to remove carbonaceousresidues, (2) re-sulfiding, and (3) reactivation with aluminum alkylcompound.

While the exact nature of the mechanism is not known and, though theapplicants do not wish to be bound by a specific theory on mechanism,there are certain things which are known to occur in the formation ofthese catalysts. When a suitable support has been impregnated with atransition metal and heat-treated at a temperature of at least 500 F.,there is believed to exist a chemical bonding between the surface of thesupport and at least some of the transition metal. This interaction isbelieved to occur between the acid sites on the support surface and thetransition metal salt. Evidence of such interaction is obtained when,for example, iron is employed as the transition metal and is impregnatedon a suitable support and heat-treated at a temperature of 500 F. inaccordance with the practice of the instant invention, and examined byMossbauer spectroscopy. Such an examination reveals that essentially alli.e. 99+% of the iron is in the +3 valence state and the Mossbauerpattern corresponds to no known oxide of iron nor to the iron saltemployed in impregnating the suitable supporting material. Consequently,this interaction or chemical bonding between the support and thetransition metal is believed to be responsible for the difficulty inreducing such a supported catalyst to metallic iron by treatment withhydrogen. For example, under conditions of 1 atmosphere hydrogenpressure at a temperature of about 1000 =F., virtually all the iron isreduced to the +2 valence state, i.e. an inactive catalyst while littleor no metallic iron is formed.

When the supported transition metal is contacted with hydrogen sulfidethere are two reactions which are believed to occur: (1) reduction inthe valence state of the transition metal due to the reducing action ofthe H 8 or the H S-H mixture and (2) replacement of at least a portionof the oxygen (or other anionic species) associated with the transitionmetal by sulfur. Since the sulfiding reactions are not trulystoichiometric, it is diflicult to write meaningful chemical equations.However, the species types believed to be present after the sulfidingreaction can be illustrated for the transition metal M.

Sulfided species bound to support Support -0M-S- or Support SMS andsulfided species are bound to support Both species are intended torepresent medium size crystallites containing 4 to 20 or more atoms of Min combination with varying amounts of sulfur and oxygen. The amount ofM in bound form and unbound form may vary considerably with the natureof M.

When the sulfided catalyst is treated with an excess of organometalliccompound, QR wherein Q represents a Group I, II or III metal, R is theorganic constituent and wherein n is equal to the valence state of Q, itis believed that the bond to the support is broken and a QR(n 1)fragment attaches to the supoprt and the metal M is alkylated by theremaining R group. The transition metal alkyl is unstable and stabilizesttself by decomposing to a hydride plus olefin, as follows:

The species R-MS and H-M+ are intended to designate small to medium sizecrystallites of the transition metal containing at least one hydride (oralkyl) group and not simply one atom of M. These crystallites maycontain 4 to 20 or more atoms of M with its anionic component (sulfur oroxygen).

Reactions similar to reactions (1) and (2) occur at other -MS bonds inthe crystallite of M which is now no longer bonded to the support. Thisresults in considerably smaller crystallites of M containing hydridegroups, e.g.

Simultaneous with these reactions there are residual -OH groups on thesupport which react with QR as follows:

(4) Support CH+QR Support OQB (1H) +RH The products of both reactions(3) and (4) contain R groups attached to Q which is also bonded tooxygen, sulfur or another anionic species. This renders the remaining Rgroups on Q less reactive for reactions (1) and (3). If the temperatureis increased substantially (above 300 F.) these R groups becomereactive. The result is (l) a further decrease in the crystallite sizeof M and (2) formation of additional hydride groups of M.

A most important reaction is that occurring between a hydridecrystallite of M (e.g. the product of reaction (3)) with an R group fromthe product of reaction (4) at elevated temperatures. This leads to astill smaller hyride crystallite of M chemically bonded to Q which isstrongly bonded to the support at the site of an original hydroxy group.

When the reaction is forced to completion at elevated temperatures inthe presence of hydrogen all the QR groups (or QH groups formedtherefrom) are reacted according to reactions (1), (3), (4) and (5) andthere results an extremely active and stable catalyst. The activity isdue to the extremely small crystallites of M hydride-sulfide and thestability is due to the strong bonding to the support, reaction (5 Useof a catalyst having an atomic dispersion of sites such as: SupportO-Q(S--M--H) with sulfur feeds generates H 8 and hydrogenalysis willprobably result in an equilibrium of the type while retaining the nearatomic dispersion property. Since the -S-MH species is probably moreactive than the --SMSH species the higher the sulfur content of the feedthe higher the hydrogen pressure and temperature required.

Thus, it is believed that the applicants have discovered a new route toa valuable and novel heterogeneous catalyst which is believed to involvechemical bonding between the support, transition metal and metallicconstituent of the organometallic reducing agent which allows for ahighy dispersed and highly active catalyst which is stable under highseverity conditions.

The selection of a suitable support material upon which the transitionmetal is impregnated is an essential feature of the instant invention.Suitable supports are those having a reasonable surface area and asufficient concentration of hydroxyl groups on the surface, whichhydroxyl groups are capable of reacting with an organometallic compound,i.e. QR or OR X where Q represents a Group I, II or III metal, Rrepresents the organic constituent i.e. an alkyl groups of theorganometallic compound or hydrogen, and wherein X equals a halogen, inorder to eliminate the RH species and attach the OR,, species to supportsurface through the oxygen atom of the original hydroxyl group.Properties and suitability of supports can be characterized in terms ofsurface area and their hydroxyl content measured by reaction with anorganometallic i.e. QR compound in the absence of a transition metal.

Those supports most suited to the instant invention include the oxidesof Groups II, III and IV of the Periodic Chart of the Elements which canbe prepared with surface areas in excess of 5 square meters per gram andwherein the hydroxyl content of the support is at least 0.1 millimole ofhydroxyl groups per gram of support. The oxides of Groups II, III and IVhaving a surface area in excess of 50 square meters per gram andcontaining a hydroxyl group content of at least 0.2 millimole ofhydroxyl groups per gram of support, determined by reaction of thesupport with the organometallic compound in the absence of thetransition metal are preferred. Aluminum oxide having a surface area ofabove about square meters per gram and a hydroxyl content of at least 1millimole per gram is the most preferred supporting material of theinstant invention. Additional, nonlimiting examples of suitablesupporting materials include magnesium oxide, zinc oxide, titaniumoxide, provided they have the necessary surface areas and reactivehydroxyl group content as described above. Many types of supports, whilepossessing the desired surface area, may or may not have the desiredreactive hydroxy group content. Nevertheless, some such supports, forexample, activated carbon, can be enhanced in hydroxyl group content bytreatment with air or an air-steam mixture at moderate temperatures,i.e. below about 1000 F. in order to form a suitable support for thecatalyst of the instant invention. Other well-known supports, such assilica, have a sufiicient surface area but may lack the necessaryconcentration of reactive hydroxyl groups and are not suitable.Silica-alumina supports, having the necessary hydroxyl groupconcentrations are effective supports and may also be employed in thepractice of the invention.

The supported catalyst of the instant invention may be prepared by anymeans conventionally used for the preparation of a supported catalyst,e.g. by impregnating the support or by precipitation in the presence ofthe support or by coprecipitation with the supporting material. Waterhas been found to be particularly suitable for the application of thetransition metal salt to the supporting materials. Preferably, thesupport is first impregnated with a water-soluble species of thetransition metal salt by contacting or immersing the support in anaqueous solution of the salt of the desired metal. Preferably, thesupport is impregnated with from about 0.1% to about 30% equivalenttransition metals; and preferably from about 1% to about 10% equivalenttransition meal, based on the total weight of the deposited equivalentmetal and support. The optimum concentration of transition metal on thesupport will depend on the nature of the transition metal and on thesurface area and hydroxyl content of the support. For example, when apure activated alumina having a surface area of about 200 square metersper gram and a hydroxyl content of about 1.2 millimoles per gram isemployed as the supporting material, and when iron is employed as thetransition metal, the optimum concentration of iron is about 0.6millimole of iron per gram support. With noble metals, for example muchlower concentration in the range of 0.1% to 1% are employed. The optimumconcentration for other transition metals which results in the highlyactive, stable catalysts of the instant invention are not known withexactitude because of the many and varied supports which can be employedherein. Nevertheless, it is believed that one skilled in the art canreadily determine these concentrations in view of the fact that they areWithin the preferred concentration ranges as described above.

The use of water to effect the chemical bonding is particularlyimportant in the impregnation of the supports with salts of the desiredtransition metal. Even iron has produced an exceptionally activecatalyst when applied to the support in the form of salts dissolved inaqueous solution. In fact, catalysts derived from aqueous solutions ofiron salts have even proved highly effective for the hydrogenation ofaromatic nucleus and carbonyl groups of organic compound, i.e. aldehydesand ketones.

The transition metals which can be employed in the practice of theinstant invention include the Groups I-B, IV-B, V-B, VI-B, VII-B, andGroup VIII metals. Preferably, the transition metals which can beemployed in the practice of the instant invention include iron, cobalt,nickel, platinum, tungsten, chromium, vanadium, molybdenum, rhenium,manganese, titanium, zirconium, niobium, palladium, rhodium, copper,silver and gold. The most preferred transition metals include iron,cobalt and nickel, platinum, tungsten, chromium, molybdenum, vanadium,rhenium and copper. Nonlimiting examples of salts which can be employedfor the application of these metals to these supports include thehalides, sulfates, nitrates, formates, acetates, propionates, molybdate,vanadates, chromates, dichromates, tungstates, manganates, titanates,zirconates, rhenates, perhenates and the like. Water soluble acids suchas perrhenic acid may also be employed. These various transition metalsdescribed above may be used alone or in combination.

The impregnated support in powder or granular form, is then treated byestablishing time-temperature relationships suitable to produce achemical change on the surface of the support and remove water andabsorbed oxygen. Suitably, the impregnated support can be heated in air,in an inert atmosphere or in vacuum, e.g. 20 to 29 inches of vacuum at atemperature of at least about 500 F. preferably 600 to 1500 F. and morepreferably from about 600 to about 1000 F. It is a critical feature, inorder to form the more highly active and stable catalyst of the instantinvention, to heat the impregnated support at a temperature above 500 F.for a period of time in the range of about 0.5 to about 4 hours andpreferably from about 1 to 2 hours. While the heat-treatment may beperformed in air or an oxygen atmosphere, it must then be followed by aperiod in an inert atmosphere in order to remove the adsorbed oxygen. Inaddition to the removal of oxygen and moisture, other importantreactions occur during this heat-treatment, as described above, in orderto render the transition metal in a form more amenable to the subsequentreaction with the organometallic compounds.

In an alternative embodiment, the impregnation and heat-treating stepscan be conducted in multiple stages. For example, the support can beimpregnated and then dried or partially dried, at low temperature. Thesupport can then be reimpregnated and again dried or partially dried.The heat treatment per se may be conducted in multiple stages, ifdesired. The impregnated support, to facilitate handling, can thus besubjected to a first rather mild heat treatment. to dry the support andthen, in a second step, to a more severe treatment to produce thedesired chemical change at the surface of this support. Supportedcatalysts, such as are supplied by the commercial catalystmanufacturers, e.g. iron, cobalt and/or nickel, alone or in combinationwith other metals such as molybdenum, tungsten, or the like are alsoamenable to such treatments to transform them to highly activecatalysts.

The then impregnated, heat-treated support after being contacted withhydrogen sulfide as described above is activated by treatment with anorganometallic compound, suitably a hydrocarbon solution of anorganometallic compound, or a hydrocarbon soluble organometalliccompound, a metallic constituent of which is selected from Groups I, Hand HI of the Periodic Chart of the Elements as in Fisher ScientificCompany Copyright 1952. Preferably the organometallic compounds includethose having the formula: QR wherein Q is equal to the metallicconstituent and is selected from Groups I-A, II and HI having an atomicnumber of from 3 to 50, n is the valence state of Q and wherein R is theorganic constituent and is selected from the group consisting ofhydrogen or the same or different, substituted or unsubstitutedsaturated or unsaturated alkyl, aryl, alkylaryl, arylalkyl or cycloalkylgroups containing up to about 20 carbon atoms. Reppresentative,non-limiting examples of the organic constituents, i.e. R include, butare not limited to methyl, ethyl, n-propyl, isopropyl, isobutyl,secondary butyl, tertiary butyl, n-amyl, iso-amyl, heptyl, n-octyl,n-dodecyl and the like; 2-butyl, 2-methyl-2-butyl, and the like;cyclopentylmethyl, cyclohexylethyl, cyclohexyl-propyl and the like;2-phenylethyl, Z-phenylpropyl, Z-naphthylethyl, methylnaphthylethyl andthe like; cyclopentyl, cyclohexyl, 2,2,1-bicycloheptyl and the like;methylcyclopentyl, dimethylcyclopentyl, ethylcyclopentyl,methylcyclohexyl, dimethylcyclohexyl, 5-cyclopentadienyl and the like;phenylcyclopentyl, and the like, phenyl, tolyl, ethylphenyl, xylenylnaphthyl, cyclohexylphenyl and the like. The more preferred metallicconstituent of the organic metallic compound i.e. Q is selected from thegroup consisting of lithium, magnesium, beryllium, zinc, cadmium,mercury, boron aluminum, gallium and indium. In addition, organometalliccompounds having the formula QR X, may be employed as the organometalliccompound of the instant invention where Q and R are identical to the Qand R having been previously described, X is a halogen, and n and m areintegers ranging from 1 to 3, the summation equal to the valence of Q.

The most preferred organometallic activating agents are the tri-alkylsubstituted products of aluminum and the dialkyl halides of aluminum,particularly those containing alkyl groups having from one to about 6carbon atoms, especially the linear alkyl groups. Exemplary of suchcompounds, Which contain up to about 18 carbon atoms in the molecule,are trimethyl aluminum, triethyl aluminum, tri-n-butyl aluminum,tri-isobutyl aluminum, diethyl aluminum hydride, diethyl aluminumchloride, diethyl aluminum fluoride and the like. Certain volatile orhydrocarbon-soluble hydrides, for example, the various known hydrides ofboron, are also suitable activating agents as well as are the Grignardreagents.

The treatment of the supported, heat-treated sulfided catalyst with theorganometallic compound can be carried out with pure or diluted metalalkyl compounds in the liquid or vapor phase. Hydrocarbon diluents ofthe paraffinic, cycloparafiinic or aromatic types are entirely suitable.The metal alkyl compound may be present in concentrations of 5% to 50%in the diluent. A solution of about 20% aluminum triethyl in aparaffinic diluent is a preferred activation system. The activationreaction is quite exothermic and it may be desirable to remove the heatof activation. The temperature during the activation step, which ismaintained in the range of from about 0 F. to about 500 F., preferablyfrom about F. to about 200 F. Considerable gas liberation occurs duringactivation and these gases are normally vented from the system. Theactivation is allowed to proceed until reaction is no longer observed,generally 0.5 hr. to 2 hrs. in contact with at least some excess ofmetal alkyl compound.

The treatment of the activated support material in order to obtain themost active and stable catalysts referred to above as the fixation stepis a critical feature of the instant invention. After the supportedsulfided catalyst has been activated with the organometallic reducingagent, it is essential that the supported catalyst be treated in thepresence of a gaseous stream containing hydrogen at a temperature of atleast 300 F. in order to form the highly active, stable, novelheterogeneous catalyst of the instant invention. Preferably, thesupported activated catalyst is treated in the presence of hydrogen at atemperature in the range of from about 300 F. to about 1200 F., morepreferably from about 400 F. to about 1200 F. and still more preferablybetween about 800 F. and 1200 F. It is essential that this fixationtreatment be conducted in the presence of a gaseous stream containinghydrogen. This fixation treatment can be carried out in the presence ofnitrogen or inert gases such as helium, argon, and the like in view ofthe fact that hydrogen is formed in situ when these inert gases areemployed. Necessarily, however, the fixation in the presence of nitrogenor inert gases such as helium, and argon will result in catalysts oflower activity than when the fixation step of the activated supportcatalyst is conducted totally in the presence of a hydrogen gas.

Although nitrogen is normally considered an inert gas, there is evidencethat it may not be truly inert when present in the fixation of thesecatalyst systems. There is some evidence that gaseous nitrogen may reactwith the transition metal species at elevated temperatures. Suchreaction which may form nitrides of the metals are obviouslyundesirable. Therefore, it is preferred that the fixation step beconducted at the above critical temperatures in the presence of agaseous stream containing or resulting in the formation in the reactionzone of from about to 100% hydrogen and more preferably from about 75 toabout 100% hydrogen. Most preferably, the fixation under theabove-described critical temperature conditions is conducted totally inthe presence of a hydrogen atmosphere. As described above, it isbelieved that the function of hydrogen during the fixation step" whenthe supported activated catalyst is treated under the criticaltemperature limitation described above, is to fix the catalyst in astable heterogeneous form and to further stabilize the transition metalcompound to a valence state in which it can more readily and completelyreact the metallic portion of the organometallic compound.

The fixation of the supported activated catalyst in the presence of ahydrogen gas under the above-described critical conditions is usuallyconducted over a period of time varying between about 1 to about 100hours, generally less time being required at higher temperatures. Asdescribed above, it is quite surprising that under optimum conditions asdescribed above, it can be shown that the activity of the catalysts ofthe instant invention increases as the length of time in which thesupported activated catalyst is being treated in the presence ofhydrogen at high temperatures, e.g. 800-1200 F. increases. This, again,is believed to be due to the fact that the instant invention results incompletion of a series of reactions leading to a chemical bondingbetween the surface of the support and the transition metal and metalconstituent of the organometallic' compound such that these metals arenot free to migrate on the surface of the catalyst and grow largecrystallites. The formation of large crystallites in conven tionalsupported catalyst is generally accepted as an important mode ofcatalyst deactivation. Thus, the catalyst of the instant invention arehighly active at extremely mild hydrogenation conditions as well asexhibiting unusual stability at high severity conditions.

The fixation in the presence of hydrogen under the above-describedtemperature conditions can also be influenced by the hydrogen pressureat which such a treatment is conducted. Generally, atmospheric or nearatmospheric pressure, from about 0.5 to about 1.5 atmospheres isemployed. However, the hydiogen partial pressure may be increased in thereaction zone up to 100 atmospheres or greater. The hydrogen partialpressure will generally decrease the time-temperature requirements forforming the chemical bonding between the supports and a transition metaland metallic portion of the organometallicic compounds.

The so-treated catalysts are then ready ror contact wun hydrogen orhydrogen-containing gases, a suitable reaction system for producinghydrogenation (or dehydrogenation) reactions. Olefins, whether singularor multiple linkage compounds, aliphatic or cyclic, and containing 2 toabout 50 carbon atoms have been readily hydrogenated to paratfins, andaromatic compounds containing from 6 to about 50 carbon atoms, and morepreferably from about 6 to about 30 carbon atoms have been saturated toproduce the corresponding cycloalkane. Acetylenic compounds, whethersingular or multiple linkage, aliphatic or cyclic in containing fromabout 2 to about 10 carbon atoms can also be hydrogenated by thecatalyst of the instant invention. In fact, catalyst formed by theimpregnation of the supports with aqueous salts of cobalt, and iron haveproven highly satisfactory despite the normally low activity attributedto cobalt and even lower activity attributed to iron for producinghydrogenation reactions.

The catalysts can be utilized as slurries or as fixed beds, movable bedsand fluidized beds, in liquid phase or vapor phase, in batch, continuousor staged operations. Hydrogenation reactions can be carried out atremarkably low temperature and pressures as contrasted with the moreconventional catalysts, whether the reaction is conducted in liquidphase or vapor phase. Hydrogenation reactions are generally conducted attemperatures ranging from about 0 F. to about 1000 F., and preferably attemperatures ranging from about F. to about 500 F. The reactions can beconducted at lower than atmospheric pressures or at supra atmosphericpressures, but generally pressures ranging from as low as about 1atmosphere to about 500 atmospheres can be employed. Preferably,however, pressures ranging from about 1 atmosphere to about 50atmospheres are employed in conducting the reactions.

These catalysts are suitable for carrying out hydrogenation reactions insystems designed to handle high heats of reaction and severe contactingproblems, without substantial deterioration and separation of catalystfrom the support. This is due in large part to the high stability andactivity of these catalysts, by virtue of which hydrogenation reactionscan be conducted at very low hydrogen partial pressures ranging as lowas from about 1 to about 200 atmospheres.

When it is desired to carry hydrogenation reactions essentially tocompletion, an excess of hydrogen over the stoichiometric requirement isused. This excess may vary from a few percent to several hundred or evenseveral thousand percent. In the latter cases, the excess hydrogen isseparated and recycled to the system. When it is desired to carry outpartial hydrogenations, the reaction can be controlled on the basis ofhydrogen concentration e.g., mol ratio of H to feed, or reactionkinetics, e.g., using an excess of hydrogen and controlling reactiontime, temperature, H partial pressure and the like.

These and other features of the invention will be understood byreference to the following illustrative examples.

The following examples present comparative data which are illustrativeof the present invention. The examples demonstrate techniques andprocedures for preparing highly active and stable heterogeneouscatalysts. The base materials are prepared by both impregnation andprecipitation techniques. Octene-l has been selected to demonstrate thehydrogenation reaction because it follows well defined first orderkinetics, and hence activities are measured in terms of reaction rateconstants. In the comparative data it will be at once apparent that thecatalysts show a remarkable enhancement in activity directlyattributable to the organoaluminum activation.

Examples 1 and 2, immediately following, demonstrate in directcomparative sense the high activity associated with activation of theorganoaluminum compound.

EXAMPLE 1 Nickel nitrate grams Ni(NO -6H O) was dissolved in sufficientwater to form 325 cubic centimeters (cc.) of the solution. This solutionwas used to impregnate 13 500 grams F-l activated alumina (8-14 meshTyler Series). Essentially all the solution was absorbed by thealuminum. The catalyst was dried in a vacuum oven at 380-390 F. toprovide a light green solid.

An electrically heated quartz tube was charged with 60 cc. of the abovecatalyst which was heated at about 800 F. in a stream of dry nitrogenfor two hours. The evolution of N was complete in about one hour at 800F. The temperature was decreased to about 600 F. and sufficient hydrogensulfide was added to give -10 percent hydrogen sulfide inthe mixture.Sulfiding was continued for 3.5 hours and the catalyst was then strippedwith nitrogen at 800 F. for one hour to remove residual 14 EXAMPLES 3-7A series of runs was made on a commercial hydrogenation catalyst. Thiscatalyst consists of -12 percent nickel (oxide form) on activatedalumina. The pelletized catalyst was crushed and screened to -50 meshparticle size. 'Results of this series of runs are given in Table I.

These results show quite clearly that sulfur compounds such astln'ophene do inhibit the activity of these catalysts at lowhydrogenation temperatures but that the eifect is largely reversible.The catalyst can be regenerated to an activity level approaching that ofthe nonpoisoned catalyst by stripping with hydrogen at elevatedtemperature.

TABLE I.-HYDROGENATION OF OCTENE-l WITH GIRDLER T-310 CATALYST Example 34 5 6 7 Catalyst activation Sulfiding only Sulfiding 1 followed Catalystfrom Exam- Catalyst from Exam- Regen. catalyst from by AlEt treat! p eple 6. Example 6. Sulfur compound None None 0.4 veight percent 0.4weight percent None.

thiophene. thiophene. Activity, k percent H 0.1 19.1 6.7 2.0 10.8.

1 Sulfiding conditions: 16 hours at 700 F. pure H23 followed H2stripping for 2 hours at 000 F.; Room temperature, liquid phase withAlEta solution for 1 hour followed by stripping with Hz for 2 hours at400 F.;

stripping with Hg for 2 hours at 600 F.

hydrogen sulfide. The catalyst analyzed 4.4 percent nickel and 1.66%sulfur or a composition of approximately NiS The above catalyst (47grams) was charged with 250 cc. of octene-l to a stirred autoclave. Ahydrogen pressure of 200 p.s.i.g. was placed on the autoclave and thecontents heated to 170 F. The pressure increased and maintained steadyat 220 p.s.i.g. There was no evidence of pressure drop and a samplewithdrawn after 15 minutes shows 100% octene by vapor chromatographicanalysis.

The temperature was increased to about 300 F., increasing the pressureto a steady value of 395 p.s.i.g. Under these conditions, the rate ofhydrogenation of the octene was about 0.3% per hour or a total of 1.43%noctane formed in 5 hours.

EXAMPLE 2 The catalyst was prepared and sulfided as described inExample 1. After the sulfiding was complete, the catalyst was cooled toroom temperature under dry nitrogen in the quartz tube. The catalyst badwas flooded from the bottom with a 20 percent solution of triethylaluminum in n-heptane. A vigorous reaction with considerable gasevolution occurred and the temperature in the catalyst bed reached amaximum of 185 F. The reaction subsided after a few minutes and, afterstanding for 35 minutes, the essentially colorless liquid was drainedofi. Uncombined aluminum triethyl was removed by stripping the catalystwith dry nitrogen at 400 F. for one hour.

The above catalyst (50.5 grams) was charged with 250 cc. of octene-l tothe stirred autoclave, care being taken to avoid exposing the catalystto air. The autoclave was pressured to 200 p.s.i.g. with hydrogen andthe temperature increased to 170 F. A pressure drop of 8-10 lbs/minutewas observed, and the pressure was maintained in the range of 155-200p.s.i.g. by incremental addition of hydrogen. Samples were withdrawnperiodically and analyzed by vapor chromatography with the followingresults:

Reaction time, minutes Percent:

Octane 29. 8 89. 5 100 Octenc 70. 2 10. 5 Nil 1 AlEt (aluminum triethyl)treat conditions: 3 Catalyst regenerated by EXAMPLES 8-9 A commercialhydrofining catalyst consisting of nickeltungsten supported on activatedalumina (65 cc. catalyst) was placed in the quartz tube and treated for17 hours at about 800 F. with dilute hydrogen sulfide (about 10 percenthydrogen sulfide in nitrogen). The catalyst was stripped with purenitrogen at 800 F. for one hour to remove free hydrogen sulfide. Thecatalyst was analyzed 4.3% Ni, 17.0% W and 8.6% S after the sulfidingtreatment.

This sulfided catalyst (40 grams) was tested for hydrogenation ofoctene-1 at 170 F. and 400 p.s.i.g. hydrogen pressure and showed verylow activity. The same catalyst was then placed back in the quartz tubeand freed of residual hydrocarbon by stripping with dry N at 600 F. forone hour. The catalyst was then activated with aluminum triethyl asdescribed in Example 2. The activity was then determined fromhydrogenation of octene-1. Activities of catalyst in the sulfided formand AlEt activated sulfided form are compared below:

The aluminum alkyl activated sulfided catalyst is thus more than 20times more active than the sulfided form of the same catalyst.

EXAMPLE 10 A catalyst was prepared by impregnating 100 gms. F-l aluminawith ml. of solution containing 0.56 gm. Pt as H PtC1 Essentially allthe solution was absorbed and the catalyst, after drying in the vacuumoven, contained 0.5 percent Pt.

A quartz tube was charged with 51 gms. of the above catalyst and heatedfor 1 hour at 800 F. in dry nitrogen. The gas was changed to pure H 8and the catalyst was sulfided at 800 F. for 17 hours. The sulfiding gaswas cut out and the catalyst stripped with dry nitrogen for one hour at800 F.

After cooling, the catalyst was discharged into an autoclave containing25 0 ml. octene-1. Hydrogenation at 300 F., then at 350 F., for twohours at 600 p.s.i.g. hydrogen pressure showed no evidence of reactionas determined by pressure drop. The discharged liquid product showed nosignificant concentration of octane by vapor chromatography.

The catalyst was placed in the quartz tube and dried by stripping withdry nitrogen at 400 F. for one hour. After cooling to room temperature,the catalyst bed was flooded with a percent solution of AlEt inn-heptane. The temperature reached a maximum of 180 F. After about onehour the solution was withdrawn and the catalyst was heated at 400 F.for 2 hours in a flow of dry hydrogen.

The above catalyst was charged to the autoclave with 250 ccf octene-land the hydrogenation carried out at 300 F. and 600 p.s.i.g. hydrogenpressure. The initial rate of hydrogen absorption was 70-80 pounds perminute and the reaction was complete in ten minutes. The product showedno detectable quantity of octene by vapor chromatography.

EXAMPLE 11 The high activity catalyst from Run 10 was rinsed twice withbenzene and charged to the autoclave with 250 cc. benzene. Hydrogenationat 300 F. and 600 p.s.i.g. hydrogen pressure showed an initial hydrogenabsorption rate of 20-25 pounds per minute. Only cyclohexane resultedfrom hydrogenation of the benzene. The reaction rate was determined byvapor chromatographic analysis of samples withdrawn as follows:

Percent hydrogenation Time on conditions, hr.- of benzene 1 27.5

EXAMPLE 12 200 gms. of alcoholate alumina granules (14-20 mesh) wasimpregnated with a 125 cc. of solution containing 26 grams cobaltousacetate (-4H O) to give a catalyst which, after drying, was calculatedto contain about 3 percent cobalt.

50 cc. of the above catalyst was charged to the quartz tube and heatedat 800 F. for one hour in a flow of dry nitrogen. The catalyst wassulfided with a mixture of about 10 percent hydrogen sulfide, 90 percenthydrogen for 17 hours at 800 F. After cutting out the sulfiding gas, thecatalyst was stripped with hydrogen for one hour at 800 F.

The above catalyst was tested for hydrogenation of octene-l at 300 F.and 665 p.s.i.g. hydrogen pressure. About 1.5 percent of the octene washydrogenated in one hour at these conditions.

The catalyst from the above run was charged back to the quartz tube andstripped of volatile material with dry nitrogen at 300 F. for 1% hours.The quartz tube was then flooded with a 20 percent solution of triethylaluminum giving a maximum temperature rise to 135 F. from roomtemperature. After one hour, the solution was withdrawn and the catalystgiven a final fixation at 400 F. in a hydrogen atmosphere for one hour.

The AlEt activated catalyst was then tested for octene hydrogenation at260 F. and 600 p.s.i.g. hydrogen pressure. The hydrogenation of theoctene to n-octane was complete in 6 minutes.

EXAMPLES 13-14 A catalyst was prepared by impregnating 200 gms. of F-lalumina with a solution prepared by dissolving 3 cc. pyrrhenic acid (1.3gms. Re/ cc.) to a total volume of 120 cc. in water. All solution wastaken up by the alumina. The dried catalyst contained approximately 2percent rhenium on the support.

The above catalyst (50 cc.) was sulfided in pure hydrogen sulfide at 800F. for 16 hours, then stripped with hydrogen and cooled under hydrogen.Activity was determined for hydrogenation of octene-l at 600 p.s.i.g.hydrogen pressure. There was no measurable activity at 170 and slightactivity at about 300 F.

The same catalyst was placed back in the quartz tube,

16 stripped with dry nitrogen at 800 F. to remove residual hydrocarbons,then activated with triethyl aluminum.

The catalyst bed was flooded from the bottom with a 20 percent solutionof triethyl aluminum in n-heptane. A vigorous reaction with considerablegas evolution occurred and the temperature in the catalyst bed reached amaximum of 185 F. The reaction subsided after a few minutes and afterstanding for 35 minutes the essentially colorless liquid was drainedoff. Uncombined aluminum triethyl was removed by stripping the catalystwith dry hydrogen at 400 F. for one hour.

The activity was again determined for hydrogenation of octene-l. Theactivity enhancement attributed to activation by triethyl aluminum wasabout 20-fold as shown in the table below:

The catalyst used in Example 14 was used to hydrogenate 250 cc. of anequal volume mixture of benzene and octene-l at 260 F. and 600 p.s.i.g.hydrogen pressure. Analysis of samples withdrawn periodically showedthat the octene-l was hydrogenated selectively.

Reaction time, hours 0.5 1.0 1. 6 2.0 5. 5

Product composition:

n-Oetane 19.6 28.5 34.3 3 43.9 31.2 21.9 15.2 12 5 6.6 Benzene 49. 249.6 50.5 1 49.5

EXAMPLE 16 A catalyst was prepared by impregnating 200 gms. F-l alumina(8-14 mesh) with a solution of 31 gms. ammonium meta tungstate (68% W)in cc. water. After drying in the vacuum oven, the catalyst weighed 223gms. and contained about 9 percent tungsten.

This catalyst (60 ml.) was charged to the quartz tube and heated at 800F. in a flow of dry nitrogen about 3 hours. The nitrogen was replacedwith a mixture of hydrogen sulfide and hydrogen (10-20% hydrogensulfide) and sulfiding was continued for 17 hours and the catalyst wasstripped with hydrogen for one hour. The analysis of the catalyst was8.9 percent W, 2.37 percent S or an approximate composition of WS Theactivity of this catalyst was determined for hydrogenation of octene-lat 300 F. and 600 p.s.i.g. hydrogen pressure. Results were as follows:

Run time, hrs.- Percent hydrogenation 1 9.5 2 14.7 3 19.5 4 22.7

The AlEt activated catalyst from Example 16 was used without furthertreatment to hydrogenate a 250 cc. charge of octene-I containing 0.1weight percent added thiophene. At 300 F. and 600 p.s.i.g. hydrogenpressure, the reaction was complete and the product entirely paraffinicafter about 1.25 hours on conditions.

,Reaction time, hours EXAMPLE 1s p The catalyst from Example 17 was usedwithout further treatment to hydrogenate a 250 cc. charge of octene-lcontaining 0.1 weight percent added octyl mercaptan at 300 F. and 600p.s.i.g. hydrogen pressure. The reaction was complete and the productentirely paraffinic after 1.25 hours on conditions.

EXAMPLE r9 v A tungsten on alumina catalyst was prepared as de- AlEt asdescribed by reference to Example 16. The AlEt activated sulfidedcatalyst was so active at 300 F. and 600 p.s.i.g. hydrogen that theactivity could notbe measured with any degree of precision. The reactionwas com plete in 5-6 minutes on conditions. The activity was determinedat 212 F. and 600 p.s.i.g. hydrogen as follows:

Reaction time, minutes- Percent hydrogenation EXAMPLE 20 The catalystfrom Example 19' was used without further treatment to hydrogenate 270cc. of benzene at 300 F. and 600 p.s.i.g. hydrogen pressure. Resultswere as follows:

Percent hydrogenation I 8 These conditions are much milder than anycondition.

known for hydrogenation of aromatics with sulfides of transition metals.The selectivity is essentially 100 percent to cyclohexane.

EXAMPLE 21 A catalyst wasv prepared by impregnating 200 gms. F-l alumina(8-14 mesh) with asolution of 27 gms. of ammonium heptamolybdate (82%M00 in 110 ml. water. The vacuum dried catalyst contained about 8percent M0 by weight.

Reaction time, hrs.-- Percent hydrogenation These results correspond toa first order reaction rate constant of about 0.1-6% hr.-

EXAMPLES 22-29 The sulfided catalyst used in Example 21 was actiyatedwith triethyl aluminum in the manner described in Example 2, the finaltreatment "at 400 'F. being carried out in the presence of hydrogen.This catalyst was also 75 analyzed for sulfur content before and'afterthe AlEt Reaction time, hours- HYDROGENATION OF OCTENE-l [Catalyst 8% Moon F-l alumina, sulfided, .AlEta activated temperature 300F.; Hzpressure, 600 p.s.i.g.]

' Additives to feed,

percent Rate Relacontlve Thlostant, activ- Example phene AlEta k ltyEXAMPLE 3 0 A commercial chromia-alumina dehydrogenation catalyst wassulfided at 950 F. for 17 hours, then at 1000 F. for 5 hours using 10-25percent hydrogen sulfide in hydrogen. This catalyst (56 gms.) was testedfor hydrogenation of octene-l at 300 F. and 600 p.s.i.g. hydrogenpressure. There was essentially no activity under these conditions(about 0.1% hydrogenation in one hour).

. The catalyst from the above operation was activated with Al-Et asdescribed in Example 2, the final heat treatment being carried out in ahydrogen atmosphere. The activity determined for hydrogenation ofoctene-l at 300 F., 600 p.s.i.g. hydrogen was as follows:

Percent hydrogenation This corresponds to an absolute reaction rateconstant (first order of 18% III-1).

EXAMPLE 31 A manganese F-l alumina catalyst was prepared by impregnating200 gms. of the alumina base with a solution of 58 gms. of manganousacetate (tetrahydrate) in 100 cc. warm water. The dry catalyst containedabout 9 percent Mn. This catalyst was heated in a-nitrogen flow at 800F.- for 5 hours, then was sulfided for 17 hours at 800 F. using amixture of hydrogen sulfide and hydrogen (IO-20% hydrogen sulfide).

The sulfided catalyst (43 gms.) was tested for hydrogenation of octene-lat 300 F. and 600 p.s.i.g. hydrogen pressure and was found to beessentially inactive (about 0.1% hydrogenation in 2 hours).

The same catalyst was then activated with AlEt as described in previousexamples; the final treatment was carried out in an atmosphere ofhydrogen at 425 F. for one hour.

The hydrogenation test on the AlEt activated manganese catalyst (300 F.,600 p.s.i.g. hydrogen, octene-l feed) gave the following results:

Reaction time, hrs.: Percent hydrogenation Although, this catalyst isconsiderably less active than most of the others, the results show veryclearly that this activation technique is also applicable to manganese.

19 EXAMPLE 32 A vanadium catalyst was prepared by impregnating 200 gms.F1 alumina with a solution prepared by dissolving 28 gms. ammonium metavanadate (NH VO in a mixture of 50 cc. monoethanolamine and 70 cc.water. The vacuum dried catalyst contained about percent V.

The catalyst was treated in a flow of dry nitrogen for 4 /2 hours at 800F. and was then sulfided at 800 F. as described in Example 31.

The sulfided catalyst (43 gms.) was tested for hydrogenation of octene-1(250 cc.) at 300 F. and 600 p.s.i.g. hydrogen pressure. The catalystshowed slight activity giving 7.1 percent hydrogenation of the octene in3 hours on conditions.

The same catalyst was then activated with AlEt as described in previousexamples. Hydrogenation activity for octene-l for the AlEt activatedcatalyst was as follows:

Reaction time, min.: Percent hydrogenation 5 62.7 82.3

This AlEt activated sulfided vanadium catalyst thus shows very highhydrogenation activity corresponding to an absolute reaction rateconstant of 13.5 percent hr.-

EXAMPLE 33 1st order Fixation kinetics AlEta Temp., Percent At treat F.Gas min. F.

As can be seen from the results as tabulated above, as the severity ofthe fixation conditions are increased, i.e. temperature increase inpresence of hydrogen, the activity of the catalyst is markedlyincreased, even when employed under significantly milder (125 vs. 300F.) hydrogenation conditions.

What is claimed is: 1. A process for forming a hydrogenation catalystwhich comprises:

impregnating a support containing at least 0.1 millimole of hydroxylgroups per gram of support with an aqueous solution of a salt of atransition metal wherein the transition metal is selected from the groupconsisting of Groups I-B, IV-B, V-B, VI-B, VII-B, and Group VIII metalsand mixtures thereof:

heat-treating the impregnated support at a temperature of at least about500 F. to remove liquid and adsorbed oxygen; contacting the heat-treatedimpregnated support with hydrogen sulfide at a temperature in the rangeof from 400 to about 1000 F.;

activating the heat-treated impregnated sulfided support by contactingsame with a predominantly co-valently bonded organometallic compoundhaving the formula: QR wherein Q is selected from Groups I,

II or HI metals of the Periodic Chart of the Elements, R is selectedfrom the group consisting of hydride, and alkyl, aryl, alkaryl, aralkyl,or cycloalkyl radicals containing from 1 to about 20 carbon atoms andwherein n ranges from I1 to 3 and satisfies the valence of Q;

and thereafter treating the activated supported sulfide metal complex inthe presence of hydrogen at a temperature of at least about 300 F.

2. The process of claim 1 wherein the support is selected from oxides ofGroups II, III and IV of the Periodic Chart of the Elements.

3. The process of claim 1 wherein Q has an atomic number of from 3 to 50and wherein QR is a tri-alkyl aluminum.

4. The process of claim 1 wherein the activated supported sulfide metalcomplex is treated in the presence of hydrogen at a temperature above400 F.

5. The process of claim 1 wherein the heat-treated impregnated supportis contacted with a gaseous stream containing from about 0.1 to about20% hydrogen sulfide.

6. A process for forming a sulfided hydrogenation catalyst whichcomprises:

impregnating a support having a surface area of at least 5 square metersper gram and containing at least 0.1 millimole of hydroxyl groups pergram of support with an aqueous solution of a salt of a transition metalwherein the transition metal is selected from the group consisting ofGroups I-B, IV-B, V-B, VI-B, VII-B, and the Group VIII metals andmixtures thereof;

heat-treating the impregnated support at a temperature of at least about500 F. in an inert atmosphere;

contacting the heat-treated impregnated support at a temperature in therange of from 400 to about 1000 F. with a gaseous stream containing fromabout 0.1 to about 20% hydrogen sulfide;

activating the heat-treated impregnated sulfided support by contactingthe same with a predominantly co-valently bonded organo-metalliccompound having the formula QR wherein Q is selected from Groups I, Hand III metals of the Periodic Chart of the Elements having an atomicnumber of from 3 to 50, R is selected from the groups consisting ofhydride and alkyl, aryl, alkaryl, aralkyl and cycloalkyl radicals havingfrom 1 to 20 carbon atoms, and wherein n ranges from 1 to 3 andsatisfies the valence of Q and thereafter treating the activatedsupported sulfide metal complex in the presence of hydrogen at atemperature of at least about 400 F.

7. The process of claim 6 wherein the support is selected from theoxides of Groups II, III and IV of the Periodic Chart of the Elements.

8. The process of claim 6 wherein the amount of transition metalimpregnated on the support is in the range of from 0.1 to about 30%based on the total weight of the deposited equivalent metal and support.

9. The process of claim 6 wherein the impregnated support isheat-treated in an inert atmosphere at a temperature in the range offrom about 600 to about 1500 F.

10. The process of claim 6 wherein the heat-treated impregnated supportis activated by contacting the same with a hydrocarbon solution of atri-alkyl aluminum wherein the alkyl groups contain from 1 to about 6carbon atoms.

11. The process of claim 6 wherein the activated supported sulfide metalcomplex is treated in the presence of hydrogen at a temperature in therange of from about 400 to about 1200 F.

12. The process of claim 6 wherein the activated supported sulfide metalcomplex is treated in the presence of a gaseous stream containing fromabout 75 to about hydrogen.

13. The process of claim 6 wherein the heat-treated impregnated supportis contacted with a gaseous stream containing from about 1 to about 10%hydrogen sulfide. 14. The process of claim 13 wherein the supportedmetal complex is contacted with hydrogen sulfide at a temperature in therange of from about 600 to about 800 F.

-15. A process for forming a sulfided hydrogenation catalyst whichcomprises:

impregnating a support having a surface area of at least 5 square metersper gram and containing at least about 0.1 millimole of hydroxyl groupsper gram of support with an aqueous solution of a salt of a transitionmetal selected from Groups I-B, IV-B, V-B, VI-B, VII-B and Group IIImetals and mixtures thereof; heat-treating the impregnated support in aninert atmosphere at a temperature in the range of from about 600 toabout 1500 F.;

contacting the heat-treated impregnated support with a gaseous streamcontaining from about 1 to about hydrogen sulfide at a temperature inthe range of from about 400 to about 1000 F.;

activating the heat-treated impregnated sulfided support by contactingsame with a hydrocarbon soluble trialkyl aluminum compound wherein thealkyl groups contain from 1 to about 6 carbon atoms; and

thereafter treating the activated supported sulfided metal complex inthe presence of hydrogen at a temperature of at least about 300 F.

16.The process of claim wherein the support is se- "lected from theoxides of Groups II, III and IV of the Periodic Chart of the Elements.

17. The process of claim 15 wherein the support has a) surface area ofat least 50 square meters per gram and a hydroxyl group content of atleast about 0.2 millimole of hydroxyl groups per gram of support.

18. The process of claim 15 wherein the support is aluminum oxide havinga surface area of above about 100 square meters per gram and a hydroxylcontent of at least 1 millimole per gram of support.

19. The process of claim 15 wherein the support is impregnated with anaqueous salt of a transition metal selected from the group consisting ofiron, cobalt, nickel, platinum, tungsten, chromium, molybdenum,vanadium, rhenium, copper and mixtures thereof.

20. The process of claim 15 wherein the impregnated support isheat-treated in an inert atmosphere at a temperature in the range offrom about 600 to about 1000 F.

21. The process of claim 15 wherein the amount of trialkyl aluminumcompound in the hydrocarbon diluent is in the range of from about 5-50%22. The process of claim 15 wherein the activated supported sulfidemetal complex is treated in the presence of a gaseous stream containingfrom about to about hydrogen at a temperature in the range of from about400 to about 1200 F.

23. The process of claim 22 wherein the activated supported sulfidemetal complex is treated in a hydrogen atmosphere at a temperature inthe range of from about 800 to about 1200 F.

24. The process of claim 21 wherein the supported metal complex iscontacted with hydrogen sulfide in the vapor phase at a temperature inthe range of from about 600 to about 800 F.

25. The process of claim 15 wherein the supported sulfide metal complexformed by contacting the supported metal complex with a gaseous streamcontaining from about 1 to about 10% hydrogen sulfide is contacted witha stripping reagent selected from the group consisting of hydrogen,nitrogen, or inert gases at a temperature in the range of from about 400to about 1000" F. in order to remove residual hydrogen sulfide.

26. The process of claim 25 wherein said stripping reagent is nitrogen.

27. The process of claim 26 wherein said stripipng reagent is hydrogen.

References Cited UNITED STATES PATENTS 2,145,657 1/1939 Ipatneff 196-242,875,158 2/1959 Winstrom 252-439 3,153,678 10/1964 Logemann 260-6673,536,632 10/1970 KIOll 252430 3,415,759 12/1968 Johnson 252-4553,113,931 12/1963 Voltz 252-442 3,288,725 11 1/ 1966 Aftandilian 252-4473,221,002 11/ 196-5 Orzrchrowski 260-949 3,205,178 9/1965 Orzrchowski252-429 DANIEL E. WYMAN, Primary Examiner P. M. FRENCH, AssistantExaminer US. Cl. X.R.

